After the powerful South Asian earthquake, BBC News website heard from people in the Pakistani capital, Islamabad, who witnessed the devastation of Margala Towers, the upmarket building complex which collapsed .
The building was swallowed up by fog and dust
Kalim Dil Khan lives in Mustapha Towers directly opposite Margala Towers and as he opened his curtains in the morning, he saw the building crumble into a pile of rubble.
It was like 9/11. The building fell under its own weight.
It was traumatic, an incredible shock.
Everything was shaking and there was a strange noise, like an extremely strong wind blowing.
I open my curtains every morning and I see those windows, those flats, the gentlemen and ladies standing in their balconies.
But this morning, all I saw was everything being swallowed up in the fog.
For an hour I was shaken, my blood pressure shot up. I live just 50 yards away.
I've had a kidney transplant recently so I couldn't run outside with the others.
I had to sit down. When I finally got down to the ground floor I lay on my back in the lounge for an hour.
I am not allowed back into my apartment, they say it is dangerous, there are still tremors. Many are homeless. This is the month of Ramadan and we are fasting, so people are without food.
But public morale is high. People are helping one another. It feels like a lucky escape.
Right now, I am sitting outside in my car waiting for somebody to take me to my sister's house.
Omar Qureshi tried to help at Margala Towers
Omar Qureshi rushed to the scene of the collapsed building to offer his help and he says he arrived at a scene of utter carnage.
I thought it was the end of my life, the way the house was shaking.
I feel really lucky to be alive.
When we went to Margala Towers, policemen were pushing people back. It was total chaos, a scene of utter carnage.
There were crowds just standing there and watching. I wanted to do something to help the rescue workers.
They were only picking up small bricks - they didn't appear to be doing any work.
Pakistan does not have adequate equipment.
I've always thought that if something like this arises, I would go out and help but the police wouldn't let me help.
I think about 50 people are still trapped. I believe only 10 have been rescued. Half of those people might be dead.
Faisal Arshad was intrigued by the fact that only the link towers collapsed
Faisal Arshad is an architect who lives very close to Margala Towers. He is concerned about plans to build more high-rise complexes in Islamabad.
I was just sitting in my lounge when suddenly there were great tremors.
I didn't know what was happening. We rushed out of the house, without slippers, anything. The walls were shaking and everything was falling off shelves, the sound was horrifying.
I went to Margala Towers, which is very close by, because I just couldn't believe it had collapsed.
It was such a big building.
In previous earthquakes, I know mud houses collapsed, easily - but commercial apartment buildings?
As an architect, I noticed something interesting. If you look at the picture you will see that the complex has seven or eight units built together.
Two of the link units are shattered. The buildings either side are still standing, which is quite peculiar structurally. Were the collapsed units properly integrated into the main structure?
Islamabad is a place which wants to build more high towers - I don't think we are prepared for anti-seismic designs. This has to be a major concern.